DEVKLOPEMENT OF INSECTS. 



•273 



egg, which is deposited by the butterfly, gives birth 

 to a caterpillar ; an animal, which, in outward 



shape, bears not the slightest resemblance to its 

 parent, or to the form it is itself afterwards to 

 assume. It has, in fact, both the external appear- 

 ance, and the mechanical structure of a worm. 

 The same elongated cylindric shape, the same 

 annular structure of the denser parts of its integu- 

 ment, the same arrangements of longitudinal and 

 oblique muscles connecting these rings, the same 

 apparatus of short feet, with claws, for facilitating 

 progression ; in short, all the circumstances most 

 characteristic of the vermiform type are equally 

 exemplified in the diflerent tribes of caterpillars, as 

 in the proper Annelida. 



But these vermiform insects have this peculiarity, 

 that they contain in their interior the rudiments of 

 all the organs of the perfect insect. These organs, 

 however, are concealed from view by a great num- 

 ber of membranous coverings, which successively 

 invest one another, like the coats of an onion, and 



Fig. 145 are the eggs; Fig. 146, the Larva, or caterpillar; Fig. 

 147, the Pupa or chrysalis; and Fig. 148, the Imago, or perfect 

 insect. 



VOL. I. T 



